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3 years ago

WWhat do these substances have in common?

Chemistry

2 answers:

olga2289 [7]3 years ago

8 0

Answer; Option A is correct

Explanation:

Matter is substance which is made up of atoms
Matter is a substance which occupies physical space

All the given four substance are matter :

Apple juice is a mixture.

Helium gas is a pure substance.

Salt water is mixture.

Copper wire is a pure substance.

But all of them are composed of atoms.

Mariana [72]3 years ago

4 0

The answer is that they are Pure substances

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Example of electrovalent bond

olchik [2.2K]

Explanation:

<h2>hope it helps.</h2><h2>stay safe healthy and happy..</h2>

4 0

3 years ago

Read 2 more answers

If a 95.27 mL sample of acetic acid (HC2H3O2) is titrated to the equivalence point with 79.06 mL of 0.113 M KOH, what is the pH

KATRIN_1 [288]

Answer:

8.73

Explanation:

The concentration of acetic acid can be determined as follows:

$M_1V_1 = M_2V_2\\(KOH) = (CH_3COOH)$

$M_{KOH}=0.113 M\\V_{KOH}=79.06 mL$

$V_{CH_3COOH}=95.27 \\\\M_{CH_3COOH)=?????$

$M_{CH3COOH} = \frac{M_{KOH}*V_{KOH}}{V_{CH_3COOH}}$

$M_{CH3COOH} = \frac{0.113*79.06}{95.27}$

$M_{CH3COOH} = 0.094 M$

Moles of $CH_3COOH$ = $95.27* 10^{-3}* 0.094$

=0.0090 moles

Moles of $KOH = 79.06*10^{-3}*0.113$

= 0.0090 moles

The equation for the reaction can be expressed as :

$CH_3COOH$ $+$ $KOH$ -----> $CH_3COO^{-}K^+$ $+$ $H_2O$

Concentration of $CH_3COO^{-$ ion = $\frac{0.0090}{Total volume (L)}$

= $\frac{0.0090}{(95.27+79.06)} *1000$

= 0.052 M

Hydrolysis of $CH_3COO^{-$ ion:

$CH_3COO^{-$ $+$ $H_2O$ -----> $CH_3COOH$ $+$ $OH^-$

$K = \frac{K_w}{K_a} = \frac{x*x}{0.052-x}$

⇒ $\frac{10^{-14}}{1.82*10^{-5}}= \frac{x*x}{0.052-x}$

= $0.5494*10^{-9}= \frac{x*x}{0.052-x}$

As K is so less, then x appears to be a very infinitesimal small number

0.052-x ≅ x

$0.5494*10^{-9}= \frac{x^2}{0.052}$

$x^2 = 0.5494*10^{-9}*0.052$

$x^2 = 0.286*10^{-10$

$x = \sqrt{0.286*10^{-10$

$x =0.535*10^{-5}M$

$[OH] = x =0.535*10^{-5}$

$pOH = -log[OH^-]$

$pOH = -log[0.535*10^{-5}]$

$pOH = 5.27$

pH = 14 - pOH

pH = 14 - 5.27

pH = 8.73

Hence, the pH of the titration mixture = 8.73

8 0

3 years ago

Which of the following values is measured the LEAST precisely? * 22mL 45.2mL 50mL 100mLchem

nekit [7.7K]

Answer:

If you're looking at the data as a whole, it would most likely be 100ml.

Explanation: The definition of precise is data close together so 100ml is furthest away from the other recorded numbers

7 0

3 years ago

A balloon filled with helium has a volume of 6.9 L. What is the mass, in grams, of helium in the balloon?

balandron [24]

Answer : The mass of helium gas in the balloon is, 1.23 grams.

Explanation : Given,

Volume of helium gas = 6.9 L

First we have to calculate moles of helium gas at STP.

As we know that, 1 mole of substance occupy 22.4 L volume of gas.

As, 22.4 L volume of helium gas present in 1 mole of helium

So, 6.9 L volume of helium gas present in $\frac{6.9L}{22.4L}\times 1mole=0.308mole$ of helium

Now we have to calculate the mass of helium gas.

$\text{Mass of He gas}=\text{Moles of He gas}\times \text{Molar mass of He gas}$

Molar mass of He gas = 4 g/mol

$\text{Mass of He gas}=0.308mol\times 4g/mol=1.23g$

Thus, the mass of helium gas in the balloon is, 1.23 grams.

6 0

3 years ago

1. Determine the final volume of a 1.5 M HCl solution prepared from 20.0 mL

nadezda [96]

Explanation:

Because molarity is classified as moles of solute per liter of water, dilution of the water may result in a reduction of its concentration.

Therefore, because the amount of moles of solute has to be constant for dilution, you will use the molarity and volume of that same target solution to calculate how many moles of solute will be present in the sample of the stock solution that you dilute.

c = $\frac{n}{v}$